1. Field of the Invention
The present invention relates to a signal distribution system for distributing and interconnecting cable television (CATV), satellite, telephone data, and infra-red (IR) control signals among a plurality of outlets at a site.
2. Description of the Related Art
It is often desirable to transmit various types of signals to or between different components or appliances in a given site or location. For example, in a residential site (e.g., a xe2x80x9chousexe2x80x9d), it may be desirable to distribute telephone data signals, digital broadcast satellite (DBS) signals, IR control signals, and CATV signals to different locations and components throughout the house. Each such location and component is typically associated with a given outlet having input and output terminals coupled to transmission media such as cables.
In some current usages, various signals are passed through control equipment and routed to fixed destinations (outlets) in the house. One problem that arises in such situations is that installation personnel and the homeowner are required to plan where they want to place a satellite receiver in advance of installation. Such estimation is often difficult, and such an approach also makes it costly to change the location of a satellite receiver. In addition, this approach typically leads to a limited number of DBS lines, for example two, which may be insufficient if the homeowner desires to use more than two satellite receivers. Further, in such approaches there is a lack of integration in the distribution of telephone data, CATV, and DBS signals. This leads to a lack of symmetry, flexibility, and accompanying drawbacks.
IR signals are also employed for data transmission or control purposes at such sites. IR remote control devices are typically used that emit a coded IR signal to control a device having a corresponding IR target. It is desirable to allow such an IR controller in one location of the house to be used to control a device located in another location in the house. Various techniques have been used to accomplish this. For example, IR repeaters may be set up to guide the controlling IR signal from one room to another. Alternatively, the IR signal may be converted to a wireless (radio frequency, or RF) signal, and received at location to be controlled, and converted back to IR via an LED (light-emitting diode) so that it can be received by the IR target of the device to be controlled. Other solutions involve using an extra telephone pair to send the electric version of the IR signal through the house. However, such solutions require an independent, separate network (xe2x80x9coverlayxe2x80x9d network) which is not integrated with an integrated signal distribution network.
A coaxial (coax) line used by the device to be controlled may also be used to transmit such a signal to another location in the house. Unfortunately, transmission of such signals over a coaxial line shared by other devices such as TV tuners, DBS equipment, and the like, can damage this equipment. This is because the electrical signal used to drive an IR emitter (e.g., an LED and related circuitry) and transmitted via a coaxial line is a relatively low-frequency (e.g., a few kHz) series of DC pulses of either 0 to 5 V or 0 to 12 V amplitude. TVs and other devices, however, receive RF signals typically in a range of 54-750 MHz, via coaxial cables. (Other signals, such as DBS signals, may be transmitted at even higher frequencies, e.g. in the range of 950-1600 MHz.) A series of comparatively low frequency AC square waves having an amplitude in the range of 5-12 V (the electrical IR signal) appears as a DC signal to equipment designed to receive and transmit RF or higher-frequency signals. Thus, the electrical signal used to drive an IR LED may be referred to herein as a DC IR signal, because it appears as a DC signal to such equipment. Sending a xe2x80x9cDCxe2x80x9d signal of this sort of 5 to 12 V over the coaxial line can damage TV tuners, DBS equipment, and other comparatively high-frequency-compatible devices coupled directly or indirectly to the coaxial line.
This potential damage can be avoided by providing a special coaxial outlet. However, such a solution would most likely be more expensive than the standard outlet. Further, since it would probably not be obvious in advance where to place these special outlets, they would have to be added after initial construction to those specific locations where they are needed which is a less than ideal situation.
A system, apparatus, and method for distributing signals. A plurality of outlets has at least a first outlet coupled to an IR target for providing a first local comparatively low-frequency electrical IR signal in response to an IR signal received by the IR target. At least a second outlet is coupled to an IR emitter. A distribution module is coupled to each outlet by respective first and second cables, wherein each of the first and second cables is sufficient to carry both comparatively high-frequency signals and comparatively low-frequency electrical IR signals between a respective outlet and the distribution module. The distribution module combines all local electrical IR signals received from said outlets via said respective first cables into a combined electrical IR signal and transmits the combined electrical IR signal to the IR emitter via said second cable.